I was on the PC when I noticed the kitten in a corner. I thought he was bored so I grabbed his laser toy and attempted to get him to play with it. He loves the laser and will always chase it. So when I saw that he didn't chase it I knew something was odd. I went over to him and gave the guy a pet, but he didn't move from his spot. So I picked him up and saw a small wet spot on the floor. (In before people say I'm abusing the cat) I put his nose where the wet spot was and shouted no. I then brought him to his litter box. Minutes later, I found him doing it again and I repeat what I did earlier. More minutes pass and he is trying to do it again. I once again repeat what I did the first two times. I'm not sure why he is suddenly doing this. According to the shelter medical records where we adopted him from, he was fixed. Before today he had no problems using the litter. I didn't change the brand of litter and the litter box is clean. So I'm assuming he is trying to mark his territory.
What are some other ways I can get him to stop doing this besides my method?